By Andrew Kohut

By this point in the campaign season, the projected outcome of the midterm elections has been hashed and rehashed and even inspired some wonk-on-wonk fights along the way. The conventional wisdom is that 2014 is a Republican year—the GOP will keep the House and may well win the Senate. But surprisingly, as the elections approaches, the latest round of polling suggests that Republicans might not do as well in the popular vote for the House as expected. And that, in turn, means there might not be enough of a GOP tide to give Republicans an edge in the key Senate races they need to win a majority of seats in the upper chamber.

Consider the 2010 midterms, when a wave of Tea Partiers helped Republicans retake the House. That year, the GOP won the popular vote by 7 percentage points. The latest Pew Research Center survey, by contrast, finds only a 3-point GOP advantage in this year’s midterms: 47 percent of likely voters report intending to cast a ballot for a Republican candidate, versus 44 percent for a Democrat. And these results are not outliers, nearly matching six Real Clear Politics surveys taken in early September.

So this time around, will Republicans in the House pick up fewer seats than we expect? The Pew survey identifies two important measures that offer clues: which party is more popular among all voters and which party’s supporters are most likely to turn out on Election Day.

Read the full article in Politico Magazine.